JPS58177090A - Signal recording circuit of electronic camera - Google Patents

Abstract

PURPOSE:To read out signals without being almost affected with the dark current of a pickup element, by rotating an endless recording medium with a preset signal, switching a shutter and strating the recording immediately. CONSTITUTION:A push button switch 23 is of two-stage switch constitution and a motor 21 is started for rotation with a preset pulse signal generated when a finger is touched at first. When the motor 21 reaches a prescribed number of revolutions, a pulse C is set. When the push button switch 23 is pushed in further, a pulse B is generated and a shutter 16 is opened and shutted. A pulse operating a pickup element 17, a signal processing circuit 18 and a recording head 19 is generated just after the opening and shutting of the shutter, and the recording is started immediately after the opening and shutting of the shutter.

Description

DETAILED DESCRIPTION OF THE INVENTION (G) Field of Application of the Invention The present invention relates to an electronic camera device exclusively for still images that can capture still images and record and reproduce them in an image recording device.

(2) Prior Art With the development of television cameras and magnetic recording devices, attempts have been made to replace conventional film cameras with all-electronic cameras.

A typical example is the video tape recorder (VTR,)
There is a system that combines a TV camera and a TV camera, and it is possible to record and play back various types of images such as videos, slow motion images, and still images.

However, the above-mentioned VTR system requires a large amount of recording media to record and play back video information of television images.
The device becomes complicated and large.

Therefore, a method of recording still images on an audio cassette tape recorder as shown in FIG. 1 has been proposed. (
(Special Publication No. 55-20283) This is, for example, TV camera 1.
A broadband surface flaw signal of several MH2 obtained from MH2 is recorded in a field or frame memory 2 at high speed, and the memory information is read out at a low speed to convert it into a low frequency image signal, and is converted into a low frequency image signal. This is a method of recording on a magnetic tape 5 through a magnetic head 4.

Since a small magnetic tape device such as an audio tape recorder can only record frequencies of several tens of KH1, it is not possible to directly record image signals having a frequency band of several MH2.

Therefore, it is necessary to use a field memory 2 for time axis conversion as shown in the conventional example shown in FIG.

However, the amount of information for one image is extremely large, and the field memory device is also large, making it impossible to downsize the electronic camera.

(3) Purpose of the present invention The purpose of the present invention is to provide a small and inexpensive electronic camera device exclusively for still images, which is capable of storing multiplication information in a solid-state image sensor or an image pickup tube and reading out the multiplication table information over time. Compress the frequency band of the image signal. As a result, it is not necessary to have a one-frame memory on the electronic camera side, and the electronic camera can be made smaller.

Furthermore, by recording one screen worth of signals as one round of the endless recording medium, the recording/reproducing circuit can be greatly simplified.

Regarding the memory capacity of the imaging device, the model number is MO8.
This will be explained using a shape imaging probe. 6 is a vertical shift register that sequentially switches the vertical switch group 8; 7 is a horizontal shift register that sequentially switches the horizontal switch group 10; 11 is a vertical output line; 12 is a horizontal output line; 13 is a load resistor; and 14 is a bias power supply.

The incident particles are photoelectrically converted by the photodiode group 9 and charges are accumulated in the parasitic capacitance. This charge is read out through the horizontal output line 12 by sequentially scanning the vertical switch 8 and the horizontal switch IO.

The signal charge is converted into a voltage by the load resistor 13 and taken out as a signal.

Therefore, by temporarily accumulating signals in the parasitic capacitance of the photodiode 9, the image sensor can be used as a field memory.

However, when the ambient temperature exceeds 50C, the dark current flowing through the photodiode increases, making it impossible to accumulate and store signals for a long time.

Therefore, in the present invention, an endless type recording medium is used, and an image for one frame is recorded in one revolution. As this recording medium, a magnetic tape, a magnetic drum, a magnetic disk, or the like can be considered, but here, the following will be explained using a magnetic tape (endless).

Although it is necessary to scan this magnetic tape at a constant speed, it is not desirable to keep it rotating all the time because it wastes the battery. However, if the shutter is rotated after the shutter is pressed, there is a delay in the start-up of the motor, etc., so first a preset signal is created and the magnetic tape is started before the shutter is pressed. Furthermore, signals are recorded immediately after the shutter is opened and closed.

FIG. 3 shows the recording shape of signals used in a floppy disk, and the magnetic disk 50 has sectors 51, 52, . ...and postamble 59
, preamble 60.

The preamble 60 consists of a gap section 61, a synchronization section 62, an index 63, and a gap section 64, and a fixed pattern is recorded in the postamble section 59 and gap sections 61 and 64. Furthermore, the disk 50 has an index mark 70, and this signal is used as a reference for recording/recording.
It takes the form of playback.

When such a format is applied to an electronic camera, the following first-order problem occurs. That is, it is necessary to synchronize the rotational phase of the index mark 70 and the shutter timing, but since the disk is rotating at a low speed, it may take an hour. For example, if the 7 button is pressed immediately after detecting the index mark 70, it takes time for one rotation, which is a waste of time and is not preferable from the viewpoint of dark current. Therefore, the present invention is characterized in that recording is started from an arbitrary rotational phase unrelated to the position of the index mark.

Instead, address pulses specifying the start position of the image may be added at several locations so that the correct start position can be reproduced.

(4) Examples The present invention will be explained in detail below using examples.

FIG. 4 shows an embodiment of an electronic camera according to the present invention.

15 is a lens, 16 is a shutter, and 17 is, for example, a second
MO8 type solid-state image sensor shown in the figure.

18 is a signal processing circuit, 19 is a recording head, 20 is a magnetic endless tape, 21 is a motor, 22 is a pulse generation circuit, and 23 is a shutter push button switch. The push button switch 23 is a two-stage switch, and when it is first touched by a finger, it generates a preset pulse as shown in FIG. 5(A), and this signal activates the motor 210.
Start rotation. When the rotation speed of this motor becomes constant, the pulse x, (C) is set. This pulse (C)
The shutter switch is locked so that it cannot be pressed until the cassette is inserted. Moreover, the pulse of (C) is
It remains set until recording ends. When the push button switch 23 is further pressed, a pulse (B) is generated to open and close the shutter 16 (B'). Immediately after this, a pulse (D) for operating the image sensor 17, signal processing circuit 18, and recording head 19 is generated. That is, (
Vertical and horizontal shift pulses for driving the image sensor during the period D) are generated and supplied to the image sensor 17. Further, the signal processing circuit 18 may be supplied with one frame extraction signal or the like.

If such recording is performed, the starting points of one image will be scattered on the endless tape 20, so an address signal specifying the position of the image is inserted. As for this signal, for example, after the synchronization pattern, a digital signal specifying an address can be inserted at several places on one screen.

As described above, according to one aspect of the present invention, the endless recording medium is rotated by a preset signal, and then the shutter is opened and closed. With this setting, recording can be started immediately after opening and closing the shutter, and signals can be read out almost unaffected by the dark current of the image sensor. Furthermore, even if the starting point of one image is different for each image because it is an endless type, by adding an address signal, the signal can be reproduced without error.

Regarding reproduction, it is sufficient to provide a one-frame memory or the like and convert the time axis, or to rotate an endless recording medium at high speed. As a result.

If the address signal is regenerated and the start position is detected,
This means that accurate imaging can be restored.

[Brief explanation of drawings]

FIG. 1 shows a conventional example of an electronic camera, FIG. 2 shows the structure of an MO8 type solid-state image sensor, and FIG. 3 shows a structure of an MO8 type solid-state image sensor. An example of a conventional magnetic disk format, FIG. 4 is an embodiment of an electronic camera according to the present invention, and FIG. 5 is a pulse waveform diagram when the non-inventive embodiment is operated. 1... Video camera, 2... Frame memory, 3...
...Recording amplifier s4...Magnetic head, 5...Magnetic tape, 6...Vertical shift register, 7...Horizontal shift register, 50...Magnetic disk, 51.52-5
8... Sector, 59... Ampoule, 60... Preamble, 61... Gap portion, 62... Synchronization,
63... Index, 64... Gap portion, 15
... Lens, 16... Shutter, 17... Solid-state image sensor, 18... Signal processing circuit, 19... Recording head, 20... Magnetic endless tape, 21... Motor, 22... ...Pulse generation circuit, 23...Push button switch for shutter. Figure 1

Claims (1)

[Claims] 1. In an electronic camera device equipped with an imaging device that converts original information captured through a shutter into an electrical signal, and an endless recording medium that records an output signal of the imaging device, the endless recording medium is A signal recording circuit for an electronic camera, characterized in that the shutter is rotated prior to opening and closing, and a signal including an address signal is recorded immediately after opening and closing the shutter, regardless of the rotational position of the endless recording medium.